METODOLOGI SIX SIGMA PERTEMUAN 11 ANALYZE PHASE OLEH: EMELIA SARI

Overview During the Measure Phase, the Six Sigma team collects significant amounts of data in order to measure the current performance of the process and identify the process critical X’s and Y’s. The objective of the Analyze Phase is to confirm the hypotheses, or educated guesses, made during the Measure Phase as to the root causes of the problems. Only after the team has moved beyond symptoms of the problem to the true root cause can they develop effective solutions in the Improve Phase

The Analyze Phase involves statistical analysis of collected data A statistical approach to decision making involves moving from data to information to knowledge Through the measure and analyze tools, data become information with which hypotheses can be made. Information becomes knowledge when it is successfully used to make decisions and the lessons learned from the process are completed

Statistical tools move us from data to knowledge by helping us make decisions under uncertainty. Decision making must be based on objective facts and knowledge and statistics is the science that brings clarity to what is otherwise meaningless data

Statistical Approach to Decision Making

The team should exit the Analyze Phase with a clear understanding of the root causes of the problems that prevent the process from meeting the customer CTQs identified in the Define and Measure Phases.

PROCESS ANALYSIS

Analyzing the process maps developed in the Measure Phase is one of the first steps in the Analyze Phase. This involves identifying – Value added vs. non-value-added activities – Direct customer contact steps – Sources of process delays – The impact of policies on process performance

Value Added vs. Non Value Added Activities The goal in value-added analysis is to identify the value-added steps vs. the non value-added steps and eliminate as many non-value-added steps as feasible. An activity is adding value if it meets the following three criteria: – The customer is willing to pay for it – Inputs are transformed into outputs – It is done right the first time (no rework)

Direct customer contact steps

Process Delays After the value-added analysis is completed and the customer contact points identified, the total work time of the process compared to the total process cycle time needs to be determined. Work time is defined as the amount of time that something is actually being done to the process step, whether value added or nonvalue added.

Process Delays (2) The cycle time is measured from the beginning of the process, usually the customer request, to the completion point, which is usually when the customer request is fulfilled. The difference between work time and cycle time is the delay time Only 10 to 20% of the total cycle time is work time — the other 80 to 90% is idle time

Sources of Delays and, Thus, Potential Areas for Improvement May Include the following: Approvals, especially multiple levels of approvals. Any hand-off situation, because hand-offs create queues and queues mean delays. Bottlenecks, because bottlenecks create queues. Defects, because defects create rework, which adds time to the process, thus delaying completion.

Sources of Delays and, Thus, Potential Areas for Improvement May Include the following: (2) Inspections or appraisal activities. Unclear operational definitions. Unambiguous instructions through operational definitions are needed to ensure that everyone involved in the process has the same interpretation of the work to be accomplished. Unclear accountability for the work. If everyone is responsible, no one is responsible.

The impact of policies on process performance

Choosing an Appropriate Statistical Test.

Tools for Analyzing Relationships Among Variables Scatter plots Correlation coefficient (r) Coefficient of determination (r2) Regression analysis.

Examples of Scatter Plots Indicating Direction and Strength of the Relationship Between Y and X.

Summary The Six Sigma team should exit the Analyze Phase with a clear understanding of the root causes of the problems associated with transforming the critical X’s into critical Y’s. Identification of the critical X’s starts in the Measure Phase through various measure tools and techniques. The Improve Phase focuses on improving the critical X inputs and the processes that transform the inputs into outputs. Summarizing the measurement and analysis findings at the end of the Analyze Phase will also provide the team with clearer direction on precisely what root cause problems need to be solved in the Improve Phase.

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